hepler



June 14, 1960 0.1.. HEPLER SEALING TOOL CONSTRUCTION Original FiledSept. 1, 1955 2 Sheets-Sheet 1 m m a J m w W m m .w u F m M .42 w Q o wa m W N Q w M 7 H MT m Donald L.Hepler BY D. L. HEPLER SEALING TOOLCONSTRUCTION June 14, 1960 2 Sheets-Sheet 2 Original Filed Sept.

INVENTOR. Dona/Id L.Hepler BY ATTORNEYS United States Patent SEALINGTOOL CONSTRUCTION Donald L. Hepler, New Bedford, Pa., assignor to SharonSteel Corporation, Sharon, Pa., a corporation of Pennsylvania OriginalNo. 2,855,813, dated Oct. 14, 1958, Ser. No. 531,915, Sept. 1, 1955.Application for reissue Dec. 15, 1958, Ser. No. 780,650

11 Claims. c1. s1 -9.1

Matter enclosed in heavy brackets II appears in the original patent butforms no part of this reissue specification; matter printed in italicsindicates the additions made by reissue.

My invention relates to improvements in sealing tool construction andmore specifically to a safety sealing tool which is arranged to insure,upon use, that a seal is correctly and fully crimped around theoverlapped ends of a length of strapping surrounding an object beingstrapped.

Certain prior constructions of sealing tools for crimping the usualgenerally U-shaped metal seal around overlapped ends of a piece ofstrapping positioned in surrounding relation to an object being strappedhave merely included a pair of pivotally connected handles which areoperably connected to a set of sealing jaws, so that movement of thehandles in a direction to separate the same will cause the sealing jawsto open and the reverse movement will cause the sealing jaws to close,crimping a seal positioned between said jaws. One of the majordifficulties with such a sealing tool construction is that due tonegligence or fatigue, it is possible that the workmen operating thesame may only partially close the handles of the tool resulting in thesealing jaws only partially securing the seal around the overlapped endsof strap ping, and thereby providing an insecure joinder of the ends ofstrapping.

When an object is strapped with a piece of strapping thusly insecurelysealed, there is a great danger, during movement of the object, that thelength or lengths of strapping binding the object will suddenly release,causing the object to become unbound. Further, a considerable danger toworkmen is presented through such lengths of strapping releasing, sincestrapping is formed from relatively thin metal and necessarily has sharpedge portions. A sudden release of such a length of strapping may causea portion thereof to strike a workman and thereby possibly cause seriousbodily injury.

Another prior construction of sealing tool has included in addition tothe pivotally connected handles and jaw members, a pawl and rackarrangement. The rack has usually included a series of uniformly spacedand formed teeth having a deep recess formed at either end thereof.Further, the pawl is urged by spring means to operatively engage therack teeth during movement of the handles in either the closing oropening strokes, so that when either of said strokes is commenced, it isimpossible to move the handles in the opposite direction until thestroke is completed. That is, as the handles are moved in a direction toclose the jaws, the jaws must be completely closed to full crimpingposition before they can be moved in the opposite direction to open thesame, and once the opening stroke is started, it likewise must becompleted before the jaws can again be closed.

During the closing stroke, the spring loaded pawl engages the rack teethat such an angle that the pawl will freely move out of engagement withone tooth and into "ice engagement with the next adjacent tooth as thehandles are moved toward each other, but prior to the completion of theclosing or crimping stroke, as an attempt is made to move the handles ina direction to separate the same, the pawl will firmly engage with therack teeth and prevent such movement. At the end of the crimping strokeand when the jaw members are closed in full crimping position, the pawlis received in the deep recess formed at that particular end of therack, and thusly the angularity thereof is reversed so that similar tothe crimping stroke, the opening stroke may take place, with the pawlsimilarly preventing the handles from being closed, but only allowingthem to be opened during such stroke-and after the stroke is commenced.Thus, once the crimping stroke is commenced, it must be carried tocompletion and the seal properly crimped joining'the overlapped ends ofstrapping, before the jaws can be opened and the sealing tool removedtherefrom.

One of the principal difficulties with such an arrangement of sealingtool is that although it is very desirous to have the crimping strokecont-rolled so that it must be completed before the opening stroke isstarted, the similar full control of the opening stroke frequentlypresents serious problems. For instance, atcertain times, the seal beingcrimped may become slightly wedged in one of the sealing tool jawsduring the crimping operation, and during the opening stroke of the toolit may be necessary to move the jaws quickly inwardly and outwardly torelease the seal therefrom. When both the sealing and opening strokesare fully controlled, however, it is impossible to move the jaws in thisway, so that it is necessary to use independent means to release theseal from the the sealing jaws and frequently results in damage to theseal or the strapping as well as taking up valuable production time.

A further difficulty with such a sealing tool construction is that sincethe angularity of the pawl must be changed to permit the change indirection of the handles for the sealing or crimping and openingstrokes, it is difiicult to maintain the proper spring pressure againstthe pawl for urging it into engagement with the rack teeth. Thus, by useof prior spring means there is a possibility that a slight error inassembly of the sealing tool or a slight amount of wear of such toolmight cause the pawl and rack arrangement to become inoperative, so thateither the sealing tool cannot be used, or the pawl and rack will notoperate to insure that the crimping stroke is fully completed.

It is therefore a general object of the present invention to provide asealing tool construction which eliminates the above ditliculties anddisadvantages of the prior constructions.

It is a primary object of the present invention to provide a sealingtool construction which is arranged-to insure that once the crimpingstroke is started, it must be completed before the tool can be removedfrom around a seal being crirnped.

It is a further object of the present invention to provide a sealingtool construction which includes means to insure that the crimpingstroke will be completed once it has been started, but which meanspositively and completely disengages at the end of the crimping strokeproviding complete freedom of movement of the jaws of the tool in eitherdirection during the release or opening stroke thereof.

It is still a further object of the present invention to provide asealing tool construction which includes a pawl and rack arrangementwhich is engaged during the crimping stroke preventing the crimping jawsfrom being opened during said crimping stroke and insuring that saidstroke is completed and that the seal is properly crimped, and whichpawl and rack are completely disengaged during the entire release oropening stroke of the jaws.

It is an additional object of the present invention to provide a sealingtool construction in which improved spring means is operative againstthe pawl of said construction insuring that the pawl and rack arepositively ,engaged during the crimping stroke and positively disengagedduring the opening stroke.

It is another object of the present invention to provide a sealing toolconstruction in which means are provided operative to positively engagea pawl and rack therein prior to the beginning of the crimping strokeand other means are provided to positively disengage such pawl and rackat the end of the crimping stroke and during the opening stroke.Finally, it is an object of the present invention to provide a sealingtool construction which accomplishes all of .the above objects, yet isrelatively simple in construction, ;durable in use and may bemanufactured at a minimum of cost.

These and other objects are accomplished by the parts, constructions,arrangements, combinations and subcomjbinations comprising the presentinvention, the nature of which is set forth in the following generalstatement, a preferred embodiment of whichillustrative of the best modeof which applicant has contemplated applying the principles-is set forthin the following description and illustrated in the accompanyingdrawings, and which is particularly and distinctly pointed out and setforth in the appended claims forming a part hereof.

, In general terms, the sealing tool construction comprising the presentinvention may be stated as including a normally stationary handle havingframe means thereon, an operating handle pivotally connected to theframe means, and sealing jaw means pivotally connected to the framemeans and operatively connected to the operating handle so that apivotal stroke of the operating handle in one direction closes thesealing jaws and in the opposite direction, opens the jaws. The framemeans preferably, includes a pair. of spaced side plates secured at oneportion thereof to the stationary handle in said spaced apartrelationship. g V

*' The operating handle is preferably pivoted to the stationary handleframe means by a pivotal connection of one end of said operating handleto a pin received through and extending between the frame means.Further, the sealing jaw means preferably includes a pair of spacedcrimping jaw members of usual construction for crimping a usualgenerally U-shaped metal seal around overlapped ends of a piece ofstrapping, with each of said jaw members also being pivotally connectedto the frame means in spaced apart relationship by means of pins passingthrough each of said jaw members and connected to and passing betweenthe frame means plate members.

The jaw members are pivotally connected to the frame means at a pointspaced from the ends thereof at which end they are formed in the usualhooked shape to accomplish the seal crimping operation when said jawmem- -ber hooked ends are moved in a direction toward each other. Theopposite ends of said jaw members are free from connection with theframe means and are each pivotally connected to a separate jaw linkmember.

The opposite ends of said jaw link members are pivotal- 1y connected ata common pivot point to each other and are also pivotally connected atsaid common pivot point to one end of an operating handle link member,which operating handle link member is pivotally connected at theopposite end thereof, to the operating handle at a point spaced from thepoint of pivotal connection of the operating handle to the frame means.Thus, upon pivotal movement of the operating handle, away from the framemeans, the operating handle link member acts on the jaw link members,causing the jaw link members to pivot the jaw members in reference tothe frame means in a direction to separate or open the hooked orseal-crimping ends of said jaw members. Movement of the operating handletoward the frame means likewise causes the jaw members the pawl inoperative engagement with the rack during the closing stroke and meansengageable with the pawl at the end of the closing stroke for placingthe pawl in a position disengaged from the rack during the operatinghandle opening stroke. Further, spring means is preferably associatedwith the pawl for positively maintaining the pawl in operativeengagement with the rack during the operating handle closing stroke andpositively maintaining the pawl disengaged from the rack during theoperating handle opening stroke.

The pawl is preferably'pivotally connected at the common pivot point ofthe jaw link members and the operating handle link member, with saidpawl having a rackengaging projection formed thereon, and a spring meanspositioning projection formed thereon spaced from said rack-engagingprojection. The rack is secured between the stationary handle framemeans spaced plates and is provided with a series of teeth and also witha pawl disengaging projecting portion formed to place the pawl in aposition disengaged from the rack at the end of the operating handleclosing stroke.

The spring means is preferably mounted on the operating handle linkmember and preferably includes a slidably mounted pawl-engaging pin orplunger member urged toward the pawl by resilient means, with the pinmember engaging the pawl between the pawl rack-engaging projection andthe pawl spring means positioning projection during the opening strokeof the operating handle for maintaining the pawl disengaged from therack, and engaging the pawl at the side of the spring means positioningprojection opposite from the pawl rack-engaging projection during theoperating handle closing stroke for maintaining the pawl in operativeengagement with the rack. Finally, the: operating handle is formed witha pawl-engaging projecting portionengageable with the pawl at the end ofthe operating handleopening stroke for moving the pawlinto a position inengagement with the rack.

Thus, as the operating handle is moved in the opening stroke, the pinmember of the spring means is engaged between the pawl rack-engagingprojection and the pawl spring means positioning projection, maintainingthe pawl in a position disengaged from the rack. As the operating handlereaches the end of the opening stroke, the pawlengaging projectingportion on the operating handle engages the pawl, and continued movementof the operating handle toward fully open position moves the pawl intoengagement with the rack, with such movement of the pawl being permittedby the spring means pin member passing over the pawl'spring meanspositioning projection to the side of said projection opposite from thepawl rackengaging projection. Also," as the operating handle reaches theend of its closing stroke, the rack pawl-disengaging projecting portionengages the pawl, and continued closing movement of. the operatinghandle causes the pawl to be moved to a position disengaged from therack, during which movement, the spring means pin member again movesover the pawl spring means positioning projection and is receivedbetween said projection and the pawl rack-engaging projection.

By way of example, an embodiment of the sealing tool construction of thepresent invention is illustrated in the accompanying drawings form-ing apart hereof, wherein like numerals indicate similar parts throughout theseveral views, and in which:

Fig. 1 is a side elevation of the sealing tool with a art thereof brokenaway to show internal mechanism,

with the operating handle in maximum closed position and with the pawlin a position completely disengaged from the rack;

Fig. 2, a sectional view, part in elevation, looking in the direction ofthe arrows 22 in Fig. 1;

Fig. 3, a sectional view, part in elevation, looking in the direction ofthe arrows 3-3 in Fig. 1;

Fig. 4, a sectional view looking in the direction of the arrows 44 inFig. 1;

Fig. 5, a side view of the spring means pin or plunger member;

Fig. 6, link;

Fig. 7, a side view of the spring means spring pin;

Fig. 8, a fragmentary side elevation of the sealing tool with a partthereof broken away, with the operating handle in maximum open positionand with the pawl in position to engage the rack;

Fig. 9, a fragmentary side elevation, similar to Fig. 8, with theoperating handle moved partially toward closed position and the pawlengaging the rack ahead of the first rack tooth;

Fig. 10, a fragmentary side elevation, similar to Fig. 8, with theoperating handle moved partially toward closed position and with thepawl engaged in the first rack tooth;

Fig. 11, a fragmentary side elevation, similar to Fig. 8, with theoperating handle moved nearly to maximum closed position and with thepawl intermediate its position engaged with the rack and its positioncompletely disengaged from the rack; and

Fig. 12, a sectional view, part in elevation, looking in the directionof the arrows 12-l2 in Fig. 10.

The sealing tool construction comprising the present invention includesa normally stationary handle 20' having frame means, generally indicatedat 21, mounted thereon. The frame means preferably includes a pair ofspaced side plates 22 and 23 secured to the stationary handle 20 inspaced apart relationship by the bolts 24.

Operating means in the form of an operating handle 25 is pivotallyconnected between the side plates 22 and 23 at a point spaced from thestationary handle 20 by means of the bolt 26. A generally U-s'hapedhandle stop 27 is mounted on the operating handle in alignment with andextending toward the stationary handle 20, with the stop member 27limiting the movement of the operating handle 25 toward the stationaryhandle 20, as shown in Fig. 1. Each of the stationary and operatinghandles 20 and 25 are preferably formed of cylindrical tubing, as shown.

The end of the operating handle 25 which is pivotally connected to theside plates 22 and 23 is formed generally U-shaped for a portion of saidhandle, forming the slot 28. The operating handle connecting link member29 is received within slot 28 and is pivotally connected to handle 25 bythe pivot pin 30 at a point spaced from the point of connection ofhandle 25 to the side plates 22 and 23.

The end of link member 29 opposite from its point of connection to theoperating handle 25 is formed in a generally U-shaped configurationforming the slot 31, in which slot are received the ends of a pair ofjaw connecting links 32. Links 32 are pivotally connected to the link 29by means of the pivot bolt 33.

The side plates 22 and 23 are formed with slots 34 and 35, respectively,with said slots being positioned in alignment when the side plates 22and 23 are assembled on the stationary handle 20. Pivot bolt 33 isreceived through slots 34 and 35 when in assembled position, pivotallyconnecting the operating handle connecting link 29 and thejaw-connecting links 32 for a purpose to be hereinafter described.

The ends of the jaw-connecting links 32 opposite from a side view of theoperating handle connecting the ends thereof pivotally connected to theoperating handle connecting link 29, are each pivotally connected to oneend of similar jaw members 36. Each of the jaw members 36 includessimilar aligned spaced jaw links 37, which links are pivotally connectedat either side of one. of the jaw-connecting links 32 by means of thepivot pins 38 and 39.

The jaw links 37 are formed at the ends thereof spaced from thejaw-connecting links 32 in the usual hook shaped fashion forming the jawmember seal-crimping end portions 40. Further, jaw links 37 arepivotally connected at points spaced from the end portions 40 to theside plates 22 and 23 by means of the pivot pins 41, as shown. That is,as illustrated in Figs. 1 and 2, each of the jaw members 36 is comprisedof a pair of spaced jaw links 37, and each of these jaw members 36 ispivotally connected between the spaced side plates 22 and 23, with theseal-crimping end portions 40 of each of the members 36 being positionedspaced apart and formed in a hooked shape extending toward each other.

Side plates 22 and 23 are preferably formed with recesses 42 and 43.Bridge plate 44 is assembled between each of the sets of jaw links 37 ofjaw members 36 and surrounding the pivot pins 41. Thus, recesses 42 and43 of side plates 22 and 23 and the bridge plate 44 form surfacescoacting with the seal-crimping end portions 40 of jaw members 36 toretain and crimp a seal around overlapped ends of strapping, when theend portions 40 are pivoted in a direction toward each other.

Connecting link member 29 is formed at the surface thereof facing sideplate 23, with an outwardly extend ing portion 45 in which is formed theplunger or pin guide slot or guideway 46, as best seen in Figs. 4 and 6,with said slot extending generally longitudinally of link 29. Further,guide slot 46 includes flange groove portions 47 extending laterallyfrom slot 46 spaced intermediate the depth thereof.

As shown in Figs. 4 and 5, a plunger or pin 48 having the laterallyextending flange portions 49 is slidab'ly received within guide slot 46,with the flange portions 49 being received within the flange grooveportions 47.

Plunger 48 is formed with a spring-receiving hole 50 and a generallypointed pawLengaging end portion 51.

Pawl 52 is pivotally mounted adjacent link 29 on pivot bolt 33 inalignment with plunger 48. Further, pawl 52 is formed with arack-engaging projection 53 and a reversing projection 54, as shown,with plunger 48 being positioned with the pointed pawl-engaging endportion 51 adjacent pawl 52. Thus, the end portion 51 of plunger 48 maybe selectively received between projections 53 and 54 of pawl 52, whenpawl 52 is in one position, and may be received abutting a side surface55 of pawl 52 at the side of reversing projection 54 opposite from therack-engaging projection 53, when pawl 52 is in a second position.

A pawl reversing link 56 is mounted on bolt 26 and pivot pin 30 ofoperating handle 25 adjacent the inner surface of side plate 23 andabutting operating handle 25. Reversing link 56 extends downwardly inalignment with pawl 52 and is formed with a pawl-reversing projection 57at a point spaced from operating handle 25, so that when operatinghandle 25 is pivoted in reference to the side plates 22 and 23,reversing link 56 will move with it and projection 57 will approach pawl52.

Compression spring 58 is received within the hole 50 formed in theplunger 48 and is retained mounted in said hole under compression bymeans of the spring pin 59. Spring pin 59, as best seen in Fig. 7, isformed with a small diameter portion 60 and a large diameter portion 61,thereby forming an offset 62 therebetween. Pin 59 is mounted in hole 50of plunger 48 with small diameter portion 60 received within spring 58,and with offset 62 abutting the end of spring 58.

Pawl-reversing link 56 is formed with a generally arcuate surface 63 atthe portion thereof surrounding the pivot pin 30 and the upper end oflarge diameter portion 61 of spring pin 59 abuts this arcuate surfaceand may slide along the same as operating handle 25 is pivoted inreference to side plates 22 and 23, thereby pivoting link member 29 inreference to pawl-reversing link 56. Thus, spring pin 59 at all timesresiliently urges plunger 48 toward pawl 52 through the spring 58, andthus the pointed end portion 51 of plunger 48 is at all timesresiliently urged into engagement with pawl 52.

Rack plate 64 is mounted abutting the inner surface of side plate 23 bythe screws 65, as shown, so that rack plate 64 is also in alignment withpawl 52. Rack plate 64 includes the pawl-engaging toothed portion 66 andthe pawl-reversing projection portion 67, with the teeth 68 of portion66 and also portion 67 extending in a direction toward the link 29 andpawl 52.

Because of the positioning of rack plate 64, it is necessary that thepivot pin 39, pivotally connecting the jawconnecting link 32 and jawmember 36 at the side of the frame means 21 in which the jaw-connectinglink 32 pivots in a plane adjacent rack plate 64, be of less length thanthe pivot pin 38 connecting link 32 and jaw member 36 at the oppositeside of frame means 21. Further, various spacers are used mounted on thevarious pivot pins and bolts, as needed, to properly space the sideplates 22 and 23 or to retain the various links properly assembled andpivotal, as required. Finally, a fastening bolt member 69 is receivedthrough and between the side plates 22 and 23 in the lower portion ofthese side plates for retaining them in proper assembly with the pivotpins 41 pivotally mounting the jaw members 36 in proper assembly, asshown.

For illustration of the operation of the sealing tool constructioncomprising the present invention, the sealing tool is shown in Fig. l infully closed position. In such position, the pawl 52 is pivoted to aposition disengaged from the toothed portion 66 of rack plate 64, withthe pointed pawl-engaging end portion 51 of plunger 48 being receivedbetween the rack-engaging projection 53 and reversing projection 54 ofpawl 52, thereby resiliently retaining said pawl in this disengagedposition. Further, the operating handle 25 is in its maximum downwardposition with the handle stop 27 engaging stationary handle 20, and withhandle connecting link member 29 moved to its maximum downward positioncausing the outer ends of jaw-connecting links 32 to pivot the jawmembers 36 to closed position.

To begin the seal-crimping operation, the operating handle 25 is pivotedto its maximum upward position, as illustrated in Fig. 8, and duringsuch pivoting motion, the pawl-reversing projection 57 of pawl-reversinglink 56 comes into contact with side surface 55 of pawl 52, forcing pawl52 to pivot in a clockwise direction in reference to handle connectinglink member 29, thereby forcing plunger 48 to move over reversingprojection 54 of pawl 52 and engage against side surface 55 of saidpawl. Further, this upward pivotal movement of operating handle 25causes handle connecting link member 29 to move the'pivot bolt 33upwardly moving pawl 52 up wardly to the upper end of rack plate 64 andcausing the jaw-connecting link members 32 to open or spread theseal-crimping end portions 40 of jaw members 36, as shown.

Since pivot bolt 33 is guided in its upward and down ward movement bysliding in the slots 34 and 35 of side plates 22 and 23, these slotslimit the upward movement of pivot bolt 33 and consequently the upwardmovement ofoperating handle 25. Also these slots, by maintaining thepivot pins 38 and 39 an equal distance from the vertical line of travelof the pivot bolt 33, force the jaw members 36 to pivot in a uniformmanner around the pivot pins 41, so that the seal-crimping end portions40 of jaw members 36 pivot in equal arcs and thereby uniformly crimp theseal around overlapped ends of strapping. This prevents a sea] frombeing excessively crimped at one edge and not crimped at the other edge,

8 which uneven crimping, if permitted, could result in an insecurejoinder of the ends of strapping.

After the operating handle 25 has been pivoted to the position shown inFig. 8, opening the jaw members 36 and causing the pawl 52 to pivot intorack-engaging position, the tool is placed so that the seal-crimping endportions surround the edge portions of a conven'' tional U-shaped seal,which'seal has been placed around the overlapped end portions of a pieceof strapping. The operating handle 25 is then pivoted in reference tothe frame means 21 toward the stationary handle 20.

As shown in Fig. 9, the handle connecting link member 29 has moved thepivot bolt 33 downwardly, moving pawl 52 downwardly, so that therack-engaging projection 53 on pawl 52 has engaged the upper portion ofthe toothed portion 66 of rack plate 64, said projection beingresiliently urged toward said toothed portion by the plunger 48resiliently urging pawl 52 to rotate in a clockwise direction, as viewedin Fig. 9. Further, this downward movement of pivot bolt 33 forces theinner ends of jaw-connecting links 32 downwardly forcing the pivot pins38 and 39 to separate a greater distance and pivot the jaw members 36 inreference to the frame means 21, so that the seal-crimping end portions40 of said jaw members have begun to close or move toward each other.

Continuing downward pivotal movement of operating handle 25, asillustrated in Fig. 10, the rack-engaging projection 53 of pawl 52 hasengaged the first or uppermost tooth 68 of rack plate 64, saidprojection, as before, being resiliently urged into such engagement byplunger 48 resiliently bearing against side surface of pawl 52. Also,this downward movement of pivot bolt 33 has caused the seal-crimping endportions 40 of jaw members 36 to move further inwardly towardsealcrimping position.

At this point, the seal-crimping end portions 40 of jaw members 36,coacting with the recess portions 42 and 43 of side plates 22 and 23 andthe bridge plate 44, have begun to crimp the seal around the overlappedends of strapping. Also, at this point, since the rack-engagingprojection 53 of pawl 52 has engaged the first tooth 68 of rack plate64, the operating handle 25 can no longer be moved upwardly until itsfull downward stroke has been completed. Thus, the seal-crimping endportions 40 of the jaw members 36 cannot be removed from engagement withthe seal being crimped until the sealcrimping operation is complete.

As downward movement of operating handle 25 is continued, therack-engaging projection 53 of pawl 52 continues to slide along thetoothed portion 66 of rack plate 64 engaging with the various teeth 68of said rack plate, until the pawl 52 engages the pawl reversingprojecting portion 67 of the rack plate, as illustrated in Fig. 11. Atthis point, the seal-crimping end portions 40 of jaw members 36 havecompletely crimped the seal around the overlapped ends of strapping andthe crimping operation is complete.

As shown in Fig. 11, as the operating handle 25 is moved downwardly inthe latter portion of its downward pivotal stroke, the pawl-reversingprojecting portion 67 of rack plate 64 engages pawl 52 moving the pawlin. a counter clockwise direction, as viewed, so that the pointedpawl-engaging end portion 51 of plunger 48 moves over the reversingprojection 54 on pawl 52, with Fig. 11 showing plunger 48 midway in suchmovement. Thus, as the operating handle 25 reaches its maximum downwardposition, so that the handle stop 27 engages stationary handle 20, thepointed pawl-engaging end portion 51 of plunger 48 has once again movedinto engagement with pawl 52 between rack-engagingprojection 53 andreversing projection 54 and into the position shown in Fig. 1, while jawmembers 36 have been moved to their fully closed position.

Since pawl 52 is again in a position disengaged from rack plate 64,operating handle 25 may be pivoted upwardly in its opening stroke,causing the jaw members 36 to open and release the seal which is nowfully crimped a'roundthe overlapped ends of strapping. Further, sincepawl 52 is positively retained disengaged from rack plate 64 during suchopening stroke, it is possible to move the jaw members 36 in anydirection desired to release the crimped seal therefrom.

As described in the operation of the sealing tool of the presentinvention, once the seal-crimping operation has been started and theseal-crimping end portions 40, coacting with the side plates 22 and 23and the bridge plate 44, have begun to crimp the seal around theoverlapped ends of strapping, the pawl 52 engages the teeth 68 of therack plate 64, preventing the jaw members 36 from being opened until theclosing or crimping stroke of the operating handle 25 has beencompleted. In this Way, it is impossible for the seal-crimping stroke tobe only partially completed and then the sealing tool removed, resultingin a partially crimped seal which may later fail and release theoverlapped ends of strapping.

Further, even though the crimping stroke is fully controlled and must becompleted before the opening stroke can be commenced, the pawl reversingprojecting portion 67 on the rack plate 64 completely disengages thepawl 51 from the rack plate 64 prior to this opening stroke. Thispermits complete freedom of movement of operating handle 25 andconsequently jaw members 36 during the opening stroke, so that these jawmembers may be moved in any manner necessary to disengage them from thefully crimped sea].

Also, the pawl-reversing projecting portion on rack plate 64, acting incooperation with the resiliently mounted and therefore yieldable plunger48, positions the pawl 52 positively disengaged from rack plate 64during such opening stroke, while pawl-reversing projection 57 onpawl-reversing link 56 also cooperating with plunger 48, forces the pawl52 to again move into positive rackengagingposition at the end of theopening stroke. Finally, the pawl 52 and the rack plate 64 are retainedresiliently and positively engaged during the closing stroke ofoperating handle 25 and jaw members 36 by plunger 48 hearing againstpawl side surface 55, and positively disengaged during the openingstroke of operating handle 25'and jaw members 36 by plunger 48 engagingbetween the pawl rack-engaging projection 53 and reversing projection54.

Thus, there is provided a sealing tool construction which eliminates theabove stated disadvantages of the prior constructions; which is arrangedto insure that once the crimping stroke is started, it must be completedbefore the" tool can be removed from around a seal being erimped; whichincludes means to insure that the crimping stroke will be completed onceit has been started, but which means positively and completelydisengages at the end. of the crimping stroke providing complete freedomof movement of the jaw means of the tool in either direction during therelease or opening stroke thereof; which includes a pawl and rackarrangement which is engaged during the crimping stroke preventing thecrimping jaws from being opened during said crimping stroke and insuringthat the same is completed and that the seal is properly crimped,andwhich pawl and rack are -completely disengaged during the entirerelease or open ing stroke of the jaws; in which improved spring meansis operative against the pawl of said construction insuring that thepawl and rack are positively engaged during the crimpin stroke andpositively disengaged during the opening stroke; in which means areprovided operative to positively engage a pawl and rack therein prior tothe beginning of the crimping stroke and other meansare provided topositively disengage such pawl and rack at the end of the crimpingstroke and during the opening stroke;

'10 and which is relatively simple in construction, durable in use andmay be manufactured at a minimum of cost.

In the foregoing description, certain terms have been used for brevity,clearness and understanding, but no unnecessary limitations are to beimplied therefrom, because such words are used for descriptive purposesherein and are intended to be broadly construed.

Moreover, the embodiments of the improved construction illustrated anddescribed herein are by way of example, and the scope of the presentinvention is not limited to the exact details of the construction shown.

Having now described the invention, the construction, operation and useof preferred embodiments thereof, and the advantageous new and usefulresults obtained thereby; the new and useful construction and reasonablemechanical equivalents thereof, obvious to those skilled in the art, areset forth in the appended claims.

I claim:

1. Sealing tool construction including a normally stationary handlehaving frame means thereon, an operating handle pivotally connected tosaid frame means, opposed sealing jaws pivotally connected to said framemeans and being operably connected to the operating handle so that apivotal stroke of said handle in one direction in reference to saidframe means positively closes said jaws and in the opposite directionforcibly and positively opens said jaws, the sealing jaws being operablyconnected to the operating handle for movement with said operatinghandle and movement by said operating handle between closed and openpositions, a rack operatively connected with the frame means, a pawloperatively connected with the operating handle, said rack having alength and having at least two spaced projections formed along saidlength, first means operatively connected with and movable by theoperating handle and being engageable with the pawl for placing saidpawl in operative engagement with the rack for preventing openingmovement of the operating handle during said handle closing stroke,second means operatively connected with the frame means and beingengageable with the pawl for placing the pawl in a position completelyoperatively disengaged from the rack for permitting free repeated andunrestricted reversal of movement of the operating handle duringsubstantially the entire [said] handle openingstroke and thereby freemovement of said jaws by said handle during said handle opening stroke,and resilient projection means operatively engaged with the pawl forpositively maintaining the pawl in operative engaged posi tion duringsaid closing stroke and disengaged position during said opening stroke.

2. The sealing tool construction as defined in claim 1 in which saidfirst means is positioned with respect to arid movable by the operatinghandle so that said first first means automatically engages the pawl atthe end of the operating handle opening stroke; and in which said secondmeans is positioned with respect to the frame means so that said secondmeans automatically engages the pawl at the end of the operating handleclosing stroke.

3. The sealing tool construction as defined in claim 1 in which saidfirst means includes projection means on the operating handle engageablewith the pawl at the end of said handle opening stroke; and in whichsaid second means includes projection means on the rack engageable withthe pawl at the end of the operating handle closing stroke.

4. The sealing tool construction as defined in claim 1 in which the pawlincludes a rack engaging projection and a reversing projection spacedfrom said rack engaging projection, and a side surface being formed onthe pawl adjacent said reversing projection and at the side of thereversing projection opposite from said rack engaging projection; and inwhich the resilient projection means includes a spring-pressed plungerengageable between the pawl engaging and reversing projections of thepawl 11' during the operating handle opening stroke and engageable withsaid pawl side surface during the operating handle closing stroke.

5. Sealing tool construction including anormally stationary handlehaving frame means thereon, an operating handle pivotally connected tosaid frame means, opposed sealing jaws pivotally connected to said framemeans, link means pivotally connecting the operating handle and thesealing jaws so that a pivotal stroke of said handle in one direction inreference to the frame means positively closes said jaws and in theopposite direction forcibly and positively opens said jaws whereby theoperating handle positively moves said jaws between open and closedpositions, rack means and pawl means mounted one operatively connectedwith the link means and one operatively connected with the frame means,said rack means having a length and at least two spaced projectionsformed along said length, means operatively connected with one of saidrack means and pawl means for automatically positioning the rack meansand paw] means in a position for the pawl means to engage the rack meansduring the closing stroke of the operating handle to prevent openingmovement of the operating handle during said closing stroke, and meansoperatively connected with one of said rack means and pawl means forautomatically positioning the rack means and pawl means in a completelydisengaged position during the opening stroke of the operating handle topermit free unrestricted reversal of movement of the operating handleduring substantially the entire [said] opening stroke and thereby freemovement of said jaws by said handle during said handle opening stroke.

6. Sealing tool construction including a normally stationary handlehaving frame means thereon, an operating handle pivotally connected tosaid frame means, opposed sealing jaws pivotally connected to said framemeans and being operatively connected to the operating handle so that apivotal stroke of said handle in one direction in reference to saidframe means positively closes said jaws and in the opposite directionforcibly and positively opens said jaws, the sealing jaws being operablyconnected to the operating handle for movement with said operatinghandle and movement by said operating handle between closed and openpositions, rack means operatively connected with one of said operatinghandle and frame means and pawl means operatively connected with theother of said operating handle and frame means, said rack means having alength and having at least two spaced projections formed along saidlength, means operatively connected with one of said rack means and pawlmeans for automatically positioning the rack means and pawl means in aposition for the pawl means to engage the rack means during the closingstroke of the operating handle to prevent opening movement of theoperating handle during said closing stroke, and means operativelyconnected with one of said rack means and pawl means for automaticallypositioning the rack means and pawl means in a com pletely disengagedposition during the opening stroke of the operating handle to permitfree unrestricted reversal of movement of the operating handle duringsubstantially the entire [said] opening stroke and thereby free movementof said jaws by said handle during said handle opening stroke.

7. The sealing tool construction as defined in claim in which the rackmeans and pawl means includes a pawl pivotally mounted on the linkmeans, a rack mounted on the stationary handle frame means, and the pawlbeing movable to a position to be engaged withthe rack during theoperating handle closing stroke and movable to a position completelydisengaged from the rack during the operating handle opening stroke; inwhich the means automatically positioning includes projection meansmounted on the operating handle engageable with the pawl at the end ofsaid handle, opening stroke for operably moving the pawl to a positionto be engaged with the rack; and

' 12 in which the means automatically positioning also includesprojection means mounted on the rack engageable with the pawl at the endof the operating handle closing stroke for completely disengaging thepawl from the rack. 8. The sealing tool construction as defined in claim5 in which the rack means and pawl means includes a pawl pivotallymounted on the link means, a rack mounted on the stationary handle framemeans, the pawl being mov able to a position engaged with the rackduring the operating handle closing stroke and movable to a positiondisengaged from the rack during the operating handle opening stroke, thepawl having a rack-engaging projection and a reversing projection spacedfrom said rack-engaging projection, and a side surface being formed onthe pawl adjacent said reversing projection and at the side of thereversing projection opposite from said rack-engaging projection; inwhich a spring-pressed plunger is slidabl mounted on the link meansadjacent the pawl and being urged toward said pawl, said plunger beingengaged between the pawl rack-engaging and reversing projections duringthe operating handle opening stroke, and said plunger being engaged withsaid pawl side surface during the operating handle closing stroke; andin which a first means is engageable with the pawl for positioning thepawl in rack-engaging position during the operating handle closingstroke, and a second means is engageable with. the pawl for placing thepawl in a position disengaged from the rack during the operating handleopening stroke. 9. The sealing tool construction as defined in claim 5in which the rack means and pawl means includes a pawl pivotally mountedon the link means, a rack mounted on the stationary handle frame means,the pawl being movable to a position engaged with the rack during theoperating handle closing stroke and movable to a position disengagedfrom the rack during the operating handle opening stroke, the pawlhaving a rack-engaging projection and a reversing projection spaced fromsaid rack engaging projection, and a side surface being formed on thepawl adjacent said reversing projection and at the side of the reversingprojection opposite from said rackcngaging projection; in which aguideway is mounted on the link means adjacent the pawl, aspring-pressed plunger is slidably mounted in said guideway and beingurged toward said pawl, said plunger being engaged between the pawlrack-engaging and reversing projections during the operating handleopening stroke, and said plunger being engaged with said pawl sidesurface during the op-. erating handle closing stroke; in which aprojecting portion is mounted on the operating handle engageable withthe pawl at the end of said handle opening stroke for operably engagingthe pawl with the rack; and in which a projecting portion is mounted onthe rack engageable with the pawl at the end of the operating handleclosing stroke for disengaging the pawl from the rack.

10. Sealing tool construction including a frame member, operating meansoperably connected to the frame member for movement thereon, opposedsealing jaws operably connected to the frame member for movement of'atleast one of said jaws in one direction to close said jaws and in theopposite direction to open said jaws, said at least one of said jawsbeing pivotally connected to the operating means for positive movementwith said operating means and forcible positive movement by saidoperating means in both said directions between closed and openpositions, a rack having at least two spaced teeth projecting therefrom,a pawl, one of the rack and pawl operably connected to the operatingmeans and the other of the rack and pawl operably connected to the withat least one ofthe rack and pawl for automatically positioning saidpreviously positioned at least one of the rack and pawl in a positioncompletely disengaged from the other of said rack and pawl for beingdisengaged during substantially the entire opening movement of theoperating means to permit free repeated and unrestricted reversal ofmovement of the operating means during said opening and through thepositive connection free repeated and unrestricted reversal of movementof said at least one of said jaws by the operating means during saidopening.

11. S aling tool construction including a frame member, operating meansoperably connected to the frame member for movement thereon, opposedsealing jaws pivotally connected to the frame member for movement ofsaid jaws in one direction to close said jaws and in the oppositedirection to open said jaws, said jaws being pivotally connected to theoperating means for positive movement with said operaing means andforcible positive movement by said operating means in both saiddirections between closed and open positions, a rack having at least twospaced teeth projecting therefrom, a pawl, one of the rack and pawloperably connected to the operating means and the other of the rack andpawl operably connected to the frame member, means operably connectedwith at least one of said rack and pawl for automatically positioningthe pawl in a position for the pawl to engage the rack and rack teethduring the clasing movement of the operating means with the rack teethpreventing reverse opening movement of the operating means during saidclosing, and means operably connected with at least one of the rack andpawl for automatically positioning the pawl in a position completelydisengaged from the rack for being disengaged during substantially theentire opening movement of the operating means to permit free repeatedand unrestricted reversal of the movement of the operating means duringsaid opening and through the pivotal connection free repeated andunrestricted reversal of movement of said jaws by the operating meansduring said opening.

References Cited in the file of this patent or the origmal patent UNITEDSTATES PATENTS 485,370 Brooks Nov. 1, 1892 953,507 Beale Mar. 29, 19101,071,139 Brooks Aug. 26, 1913 1,984,652 Ott Dec. 18, 1934 1,996,202Harvey Apr. 2, 1935 2,113,757 Bletso Apr. 12, 1938 2,696,747 Bergan Dec.14, 1954 2,737,071 Dibner Mar, 6, 1956 2,777,345 Reider Ian. 15, 19572,833,170 Paohter May 6, 1958

